Abstract: A car plug used to derive power comprises notches provided at alternate positions among positions obtained by circumferentially dividing a peripheral wall of a body into quarters, terminals of an elastic terminal board incorporated in the body and externally exposed through the notches, notched window-holes formed at alternate remaining positions among the positions obtained by the division into quarters, arm portions having one end connected with the peripheral wall of the body, and the other end for supporting pressure-contact members disposed in the notched window-holes so as to move in a radial direction of the body by the arm portions, the body incorporating a switching cam having cam portions switched over between positions in pressure contact with inner surfaces of arm portions of the elastic terminal board and positions to release the pressure contact, and having cam portions switched over between positions to push out the pressure-contact members to the outer surface side of the body and positions to